yes, the rear sprocket was a little challenge. not too bad tho'-i had to open the hole dia. up with a dremel tool, also,i had to squeeze the rear fender with a wood clamp to clear the chain-not too much sacrifice tho' considering the bike only cost 86.00. i've got a gal that wants me to put a kit on a new 2000.00 custom bike from italy! i strongly advised against it, but she wants to do it! no, i'll do another cranbrook tho'-it looks good,its cheap,and it rides really nice-not bad for a total investment of 230.00! have fun!!! p.s.-i also added a front brake,if you don't i think you'll burn up the little coaster brake shoes real quick!